Improvement in steam-boilers



s. TUCKER &.L'JV.QR..'BROWNELLI.

improvement in Stieam- Boilers.

Patent-ed June13, 1871.

UNITED STATES PATENT OFFIcE.

SEWALL TUCKER AND JOHN R. BROWNELL, OF DAYTON, OHIO.

IMPROVEMENT INSTEAM-BOILERS.

Specificatlonformiug part of Letters Patent No. 115,993, dated J due 13,1871.

To all whom it may concern:

Be it known that we, SEWALL TUCKER and JOHN R. BROWNELL, of Dayton, inthe county of Montgomery and State of Ohio,'have in-' vented a new anduseful Improvement in Steam-Generators; and we do hereby declare thefollowing to be a full, clear, and exact description of the same,reference being had to the accompanying drawing, in which Figure 1 is afront elevation. Fig.2 is a side elevation, partly in section. Fig. 3 isa section of water-front, showing manner of closing hand-holes.

Our invention relates to tubular or tubularand-flue steam-generators;and consists in the combination of a tubular or flue boiler withexterior hot-water tubes or fiues. The:

ticles of cool water, to be heated in turn. This result is bestaccomplished by circulating water-pipes opening'into a water-spaceconnected with the steam-generator chamber, said pipes being placed soas to receive the first and most intense heat of the furnace, andthereby heat the water to a high degree before it enters the chamberwhere itbecomes converted into steam, and where it is acted upon by thehot gases after they have expended'the principal part of their heatamong the water-pipes below.

That others may understand our invention, we will particularly describeit.

A is a boiler of ordinary tubular construction. LB is the grate; andO isthe brick setting, similar to that usually employed. The

boilerA may be raised somewhat higher than usual to afford space for thetubes D D immediately over the fire-box. The tubes D D are connected atfront and rear ends by the water front and back E F, and with the boilerA by means of the water-circulating tubes G H.

This constitutes a water-circulating heater, in

which the water is raised to or above the evaporating temperature beforeit enters the boiler A, where its transformation into steam may takeplace. The hot products of combustion pass among the tubes D beforepassing into the tubes or flues of the boiler, and therefore the greaterportion of the heat will be absorbed by the water in the tubes, and theproducts of combustion, when they leave the boiler, will be but little,if any, above the temperature of the steam in the boiler. back E F areconstructed with front and back sheets, 0 f, and the tubes D areinserted through the latter and secured in the usual manner. The frontand back sheets 6 f are firmly riveted to a frame, and stays areinserted between them where it may be necessary. The spacesE F betweenthe front and back sheetsc f connect the pipes D much more perfectlythan where two pipes are coupled with a bend, because the water is notthen compelled to follow back and forth through the tubes beforereaching the boiler, but may take the more direct course through theconnecting-chamber. Opposite each tube the sheets 0 of the water frontand back are perforated so as to permit each tube to be cleaned readilyor to be repaired, if required and each of said perforations orhand-holes is closed by a plate, J J, which is fitted to said hole fromthe outside, andis secured in place by the bolt K,

the T-head of which rests on the inner surface of the front sheet. Thescrew-shank extends through the plate J, and the nut L binds themsecurely in place and to each other.

Having described our invention, what we claim as newis- A tubular orflue boiler, A, combined with a water-circulating boiler composed oftubes or flues D united at their ends by the hollow water front and backE F, and connected with said tubular or flue boiler A by thecirculating-pipes G H, substantially as set forth.

SEWALL TUCKER. JOHN R. BROWNELL.

Witnesses:

GEo. J. ROBERTS, JAMES ANDERTON.

The water front and

